Up to 5% discount on all products. Extra: Free upgrade of Insulation to All cladding orders.

Flush Casement Window Installers

Flush Casement uPVC Windows

At Greenoak Concept & Design, our flush casement uPVC windows offer the perfect blend of modern aesthetics and timeless design. These beautiful windows open outwards, providing excellent ventilation and unobstructed views. They are crafted from Deceuninck’s industry-leading extrusions for superior thermal performance and noise reduction. Our windows are also easy to operate, highly secure, and low maintenance, making them a perfect choice for any home.

What Is A Flush Casement Window

The beautiful flush casement design gives the exterior of your window a flush appearance. The opening window closes flush into the outer frame, so it sits in line with the face of the frame, rather than standing proud, meaning there’s no visible lip when looking at your window from outside. Greenoak Concept & Design flush casement windows also feature a Smooth weld almost invisible joint on the frame corners. The result is an attractive, aesthetically pleasing appearance that gives your home a modern look like the contemporary, slim styling of aluminium Windows. Flush casement windows are becoming increasingly popular, due to their neat clean lines and flat finish.

What is the difference between storm and flush casement windows?

The main difference between flush casement windows and Flush casement windows is a storm casement window is ‘lipped’, with the openable parts protruding from the frame, whereas flush casement windows sit completely flush inside the frame when closed.

Flush – An increasingly popular design with the opening sash sitting level with the frame mimicking a traditional timber window design. This creates a smooth elegant design to the overall window giving a minimalist and uncluttered appearance when viewed from the outside of your property. Finished internally with a contemporary bevelled or traditional decorative moulding this design is suitable for both modern and traditional properties.

Casement – Casement due to its superior weather performance where the sash sits proud of the frame giving exceptional weather tightness and keeping your home warm and dry in even the worst of storms. This design provides the ultimate performance we can offer by enabling the fitting of a 44mm triple glazing unit delivering market leading U values.

Flush Casement Window Benefits

Greenoak’s flush casement windows combine style with performance. They feature a range of finishes, smooth corner joints, and bespoke options to perfectly match your home. Available in beautiful woodgrain effects and contemporary colours, you can achieve a traditional or modern look. These energy-efficient windows come in double or triple glazing, achieving U-Values as low as 1.1. The multi-chamber profile and Low-E glass work together to keep your home warm and reduce heating costs.

Greenoak Concept & Design

Flush Casement Window Gallery

Choose the perfect finish from our wide array of combinations

We understand that your windows should complement your unique style, which is why we offer a wide range of colour options and combinations for your Greenoak casement windows. From classic neutrals to bold modern tones, with the option for a different colour on the interior and exterior, there’s a perfect combination to suit any space in your home.

Flush Casement Window Furniture

While Greenoak Concept & Design excels in window performance, we understand the importance of aesthetics too. That’s why we offer a wide variety of window handle styles and colours to perfectly complement your home’s design. Our handles are built for flawless operation and outstanding quality, ensuring a smooth and long-lasting experience. Plus, we’ve recently expanded our range to include premium anti-corrosion designs, rigorously tested to withstand even the harshest weather conditions.

Frequently Asked

If you have any questions in relation to our flush casement windows, then look no further. This FAQ section answers some of the most common questions we come across. If what you had in mind is not mentioned here, please don’t hesitate to contact us and we will be happy to answer any question you may have.

A flush window is designed so the opening window sits flat and flush with the surrounding frame offering sleek lines and providing a simple yet elegant aesthetic. Flush windows are becoming increasingly popular with contemporary properties where homeowners prefer the simplistic, smooth façade this window design provides. The alternative is called a storm sash where the sash overlaps the frame offering greater perfection from heavy weather.

The flush casement windows come in a variety of finishes and colours, so the costs involved will depend on the options you choose. That said, the difference between flush casements and traditional casement windows can be upto 40% more. With an extensive range of options to choose from, you can make your windows as traditional or contemporary as you like.
At Greenoaks we offer a beautiful range of colours and natural woodgrain finishes, so there is a perfect colour to suit every property. Colours range from the traditional white uPVC finish, through to Chartwell Green and ultra-contemporary anthracite grey or black. Add a modern twist to your windows, with dual colours, complementing the inside and outside of your home.

We're trusted within our industry
Learn more about us

Based on 56 Reviews

Good original consultation with Dale, general advice without being pushy. Survey efficient and quote broken down and understandable. Very good team from Greenoak, work done as per schedule, clean and tidy. Very considerate when one of us was unwell, kept the noise down. Problem with garage door investigated and rectified very quickly. Really pleased with final result, completely transformed external appearance of house. Thanks to whole team inc Tom Jay Mike Dave Callum Ed and esp Mark and Tegan.

Kitty Heyns

Amazing service from start to finish. Wouldn't go anywhere else, highly recommend to anyone.

Danny Clark

5 * very helpful and professional great service 👍 👏 👌 highly recommended.

Roman Clark

This my second time using Greenoaks Conecept and design , I cannot vouch for them enough ! Dale and the team completed a very a high standard of work throughout on a few properties for me and would highly recommend to anyone looking .


Dale and his team are amazing! I will use them again!

Mary Dean

Highly recommend this company. Had our conservatory roof done and they did a fantastic job. They kept us informed every step of the way of what would be happening. Cleaned up at the end of each day and was very hardworking, polite and friendly.

Dale has been a star. From his first visit to give me a price, to completion of the works. Punctuality and communication of the Greenoak team (Dave/Ray/Callum) was excellent.I am so pleased with the job that Green Oak have completed for me. They were professional, tidy and worked so hard. The job is finished to a high standard and I will 100% use them again. Would highly recommend.

Maria Howe

Job was done in the hours I was told. Very efficient and happy with my new conservatory roof. Thank you and would happily recommend Greenoak

alan shinn

We recently had relacement windows and doors by Greenoak Concept. Many thanks to Dale and all the team,they are very professional, punctual, polite and leave the job in a clean and tidy condition. Very pleased with the outcome, many thanks to all at Greenoak.

Dale and the Greenoak team are fantastic; having delivered 2 large projects on our house, both on-time and on-budget (and with a laugh & smile!) we can’t recommend them enough! Thank you!

Professional job.

Nick Brennan

So far very happy with the installation . Our tired old conservatory has been totally transformed by the team at Greenoaks. They worked cleanly and efficiently whilst navigating our day today running if the house. We’re actually looking forward to the heat of summer and cold of winter!!

Dale, you and your team, thank you so much for your time and dedication. Our new composite Rock door looks and feels fantastic. It feels really good using a local company that cares about their customer from start to finish. Thank you

We have had a solid roof put on our conservatory by Green Oak. We were very impressed from the outset. Dale took time to explain every aspect of the build bringing a model of the roof so we could see the construction. Then he left us think about it and there was no hard sell. The workmen were very pleasant, friendly and worked extremely hard. Despite being one man down the other chap worked late into the evening to make sure the construction was finished on time ( rather than have to come back for a couple of hours the following day), as did the man doing the plaster boarding. Every evening the site was left tidy and all rubbish taken away once the work was finished. The plasterer and electrician also did a brilliant job and all works was finished on time. We are really happy with the end result and couldn’t recommend the firm more highly. John & Rita Dobinson

Nicky Boosey

Dale was very professional in giving us sound advice and explained the whole process from start to finish. The job commenced on time, Mike and Mark treated our home with respect and were very knowledgeable and kept us informed all the way along. The quality of work is excellent and we would recommend them.

Ian Creek

We needed 11 new windows of various sizes so we spent some time searching reviews for a highly rated but local Double Glazing window installer. Greenoak came out top of our search results, We reached out and Dale responded quickly followed by a visit a few days after. The resultant quote was very competitive versus other quotes we had received. It was an easy decision to go with Greenoak. Dale came across as very knowledgeable, friendly and genuinely customer focussed. He invited us to the showroom in Leigh where he took us through the detail to ensure we were fully aligned on requirements and expectations. We were very impressed with him and his business and by his overall professionalism. The installation took place on 20th Feb 2023 and took 4 days in total. The whole process was exemplary, we could not fault the team in any way. They were tidy, considerate and very thorough. We have had windows fitted before by various other company's but the quality of fit and finish from the Greenoak fitters was far superior. The guys worked solidly and clearly did not skimp on anything, ensuring that the windows were not only properly fitted but sealed professionally too. They did an outstanding job including clearing all of the old windows and rubbish Overall we'd rate Greenoak at 10/10. We felt reassured by their high standards of work ethics, integrity and customer satisfaction. We honestly doubt there is anyone better out there for this type of work. We therefore wholeheartedly recommend them Ian and Jenny

Fantastic job done by Greenoak, the guys were professional, friendly and a pleasure to have in my home. I couldn’t be happier with the job they did. Highly recommended.

Brilliant company, very friendly and easy to work with. Very pleased with the finished cladding on our office wall - excellent quality and good value


Replacement Conservatory Roof. Fantastic company and service from the whole team! Dale is great and gave me a quote for my new lightweight roof, great bloke and not pushy, loved the fact he gave a all in price rather than start low and add extras. The fitting team are fantastic!, Mike, Mark and Casper treated my home like their own, , great attention to detail and did everything I asked to get the perfect finish, I honestly cant find 1 fault and I am fussy! I could not be more happier with my roof!! Take my advice, Don't look anywhere else ,I cant rate them highly enough. Greenoak are the BEST!

Following our initial discussions with Dale, our expectations were already set high when it came around to installation. Some truly awful weather right at the start of the installation virtually wiped out the first two days work, and the anticipated seven day build seemed to be in jeopardy right from the start. But Mike and his crew - supplemented by two and sometimes three others, working in still inclement weather, brought the build back on schedule by the end of day five, and the plastering and electrical second fix over days six and seven meant the whole project was delivered to time, and budget meaning that our initial high expectations had even been exceeded. I have nothing but the highest regard for their workmanship and scheduling - and not forgetting Dione in the office who kept me informed throughout and efficiently managed the stage payments. In my experience it is unusual to receive a great sales pitch and then to have that exceeded by the installation teams - I couldn't recommend Greenoak's services more highly.

Our team are
ready and waiting
to help you...

Greenoak Concept & Design have been raising the standards for more than 10 years.

More about us: We’re an independent Essex-based specialists in high quality UPVC Windows, Doors, Tiled Conservatory Roofing, Wall Cladding, and Fascias, Soffits and Guttering.


Free Quotation